A car drives through Cicero, Ill., near where the Cook County Sheriff's vice unit was conducting a prostitution sting, Thursday, Aug. 15, 2013.
Scott Eisen/AP

A massive six-month human-trafficking and prostitution sting across massage parlors in Florida marked a large victory for authorities.

Despite shutting down several parlors and pressing charges against big names, the bust shed light on the widespread problem of sex trafficking in the United States that's largely under control of transnational criminal organizations.

Authorities have emphasized that they will not be pursuing charges against the workers, only those who were involved in trafficking and facilitating illegal sex work.

A six-month human-trafficking and prostitution sting across massage parlors in Florida closed ten spas last week and spawned charges for several big names in business.

Though the spotlight of the story has been on billionaire owner of the New England Patriots Robert Kraft, who was among those charged in the bust, it also renewed attention on an elusive issue that impacts thousands of people in the US each year: sex trafficking.

Sex trafficking controls the lives of thousands of vulnerable men and women in plain sight. International crime syndicates cash in from trafficking through businesses — like massage parlors, from which workers never have the chance to profit.

There are no official statistics on the number of human trafficking victims in the United States, but according to data from the National Human Trafficking Hotline, 5,147 cases were reported in the US in 2018.

The anti-trafficking nonprofit Polarishas received reports of 34,700 sex trafficking cases in the country since 2007 and found a 13 percent increase in cases from 2016 to 2017.

The organization projects the number of human trafficking victims in the United States to be in the hundreds of thousands.

According to data from the United Nations, the most common form of human trafficking is for sexual exploitation, and experts say the victims of these systems share abusive and exploitative experiences that land them in dire conditions.

Arrest records from last week's sting reportedly said investigators had found women, many of whom were from China, in "sexual servitude," living in poor conditions inside the spas, which reflects the hostile conditions faced by those caught up in sex trafficking across the country.

Some estimates project that upwards of $2.5 billion is made through businesses supported by sex trafficking, which are facilitated by large crime systems, Bradley Myles, Polaris CEO, told INSIDER.

"It’s a magnet for organized crime, it’s incredibly lucrative and they know there’s a huge market for it," Myles said.

Some women are recruited in countries like China and Korea, where they might be approached and falsely promised a better life by agents of organized crime, Myles said.

"There's a lot of fraud, deception in recruitment that happens on the front end where the women aren’t being given the full picture of what their future life is going to be like," Myles said, pointing to the pressures that might lead women to accept such offers. "We hear about women who come out of domestically violent relationships, fleeing an abusive husband, or from abusive homes where they may have had sexual or physical abuse as a kid."

"We hear about women who — their families owe some huge debt over their head, medical bill or college cost, and they've got some debt collector hunting after them," Myles added.

Though they're brought to work in America, they're still under the control of whichever organized crime group recruited them for profit.

"These places seem so innocuous, it’s a little storefront in a shopping center, but that place is the footprint of a much larger organized crime network that usually spans multiple countries and states," Myles said.

Many of the women at the busted Orchids of Asia Day Spa were from China and were not allowed to leave the spa, Martin County Sheriff Will Snyder reportedly said of investigators' findings.

But despite the hostile conditions, victims can be hesitant to report their cases for fear of retribution from law and immigration enforcement authorities because of laws against commercial sex, said Kate Mogulescu, an assistant professor of clinical law at Brooklyn Law School.

“Immigrant women, in particular, have vulnerability related to their immigrant status," Mogulescu said. "What we’ve seen over the last few years of this administration is a real stripping down of protection for immigrants who are victims of trafficking and other crimes, so that compounds the problem here."

Immigration lawyers and activists expressed concerns over new guidelines issued by President Donald Trump's administration that set a hearing before an immigration judge following denial of a T visa, which is reserved for non-citizen victims of human trafficking and their families. Experts told Foreign Policy that the summons represents the early stages of the deportation process, and complicates an individual's chance at legal immigration or asylum.

In the days after the bust, Florida law enforcement officials have emphasized they are striving to counter the root of the problem by prosecuting those involved in trafficking and collecting money from clients, not the workers.

Martin County Sheriff’s Lt. Mike Dougherty reportedly said Friday investigators intended to "follow this pyramid, this organization to try and connect them and move to the top."